Fixes typos.
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index 4fd358e..868966b 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -124,7 +124,7 @@
"We heart UTF8!™".
* ``two_basic_constraints.pem`` - An RSA 2048 bit self-signed certificate
containing two basic constraints extensions.
-* ``two_basic_constraints_csr.pem`` - A cerfificate sigining request
+* ``two_basic_constraints_csr.pem`` - A certificate signing request
for a RSA 2048 bit key containing two basic constraints extensions.
* ``basic_constraints_not_critical.pem`` - An RSA 2048 bit self-signed
certificate containing a basic constraints extension that is not marked as